The present invention relates generally to golf clubs, and is particularly concerned with a golf club head having an internal cavity which is partially or completely filled.
It is known to provide various filler materials in the cavities of golf club heads for weighting and vibration damping purposes. In U.S. Pat. No. 4,438,931 of Motomiya, the head is filled with an elastic filler material such as foamed urethane and rubber. In U.S. Pat. No. 5,649,873 of Fuller, for example, a layer of cork particles and bonding material is adhered to the inner surface of the club head cavity. However, glued cork particles are relatively heavy and not particularly durable, given the wear and tear that occurs as a result of being compressed and de-compressed with repeated impacts of the head with a ball.